1. Field of the Invention
The present invention relates to a sheet conveying device and a recording apparatus for recording an image onto a sheet.
2. Description of the Related Art
In a related-art image forming apparatus disclosed in Japanese Patent No. 4035514, to correct a skew of a sheet, the sheet is conveyed while a pair of oblique-feed rollers allow the sheet to abut against an abutment guide that is parallel to a conveying direction. The rotating surfaces of the pair of oblique-feed rollers are oblique relative to the abutment guide. The abutment guide is positioned back from a sheet conveying reference by a predetermined distance. After the skew-corrected sheet is conveyed to conveying rollers downstream of the abutment guide, the pair of oblique-feed rollers are separated from each other and the conveying rollers on the downstream side are moved by a predetermined distance in the direction perpendicular to the conveying direction while the sheet is nipped between the downstream conveying rollers, so that the sheet is returned to the sheet conveying reference. At this time, the abutment guide is positioned back from the sheet conveying reference by the predetermined distance to provide a landing distance necessary for skew correction so that the sheet smoothly abuts against the abutment guide.
After that, image formation is performed by an image forming unit on the downstream side, so that printing is performed with little skew.
In a post-processing apparatus disclosed in Japanese Patent Laid-Open No. 09-40230, a conveyed sheet is brought into contact with a stopper in the vicinity of one side edge of the sheet. After that, the sheet is rotated by 90 degrees by an oblique-feed roller so that the sheet abuts against an abutment guide placed at a sheet conveying reference, thus correcting a skew of the sheet.
In the above-described structure, disclosed in Japanese Patent No. 4035514, in which skew correction is performed using the abutment guide positioned back from the sheet conveying reference, however, it is difficult due to the stiffness of the sheet to allow the sheet to abut against the guide while the sheet is being nipped by a pair of conveying rollers upstream of the oblique-feed rollers. In addition, since the trailing edge of the sheet is not nipped by the pair of rollers on the upstream side upon skew correction, the position of the sheet is unstable. Disadvantageously, a corner of the leading edge of the sheet may abut against the abutment guide, thus causing corner folding.
In the apparatus disclosed in Japanese Patent Laid-Open No. 09-40230, when the oblique-feed roller allows the sheet to abut against the guide, the trailing edge of the sheet has to come out of the nips of the conveying rollers upstream of the oblique-feed roller. Therefore, there is a problem in that the apparatus cannot deal with a long sheet, such as a continuous sheet.